Hot air fan for driers



2 Sheets-Sheet l art/0mm .Dfl/V/EL B Vnvcs/vr D. B. VINCENT HOT AIR FAN FOR DRIERS Flled Aprll 25, 1939 Sept. 24, 1940.

Sept. 24, .1940. VD. -r

HOT AIR FAN FORDRIERS Filed April 25, 1939 '2 Sheets-Sheet 2 Patented Sept. 24, 1940 UNITED STATES PATENT OFFICE nor AIR FAN Fon nnmns Daniel Boscawe n'vincent, Winter Haven, Fla. Application April 25, 1939, Serial No 270,006

8 Claims. 230-209) I This invention relates to fluid impellers par- 4 bodiment of the invention may be made within ticularly adapted for combining two or more fluid streams, commingling the two fluids and discharging the combined fluids. It is, therefore, an object-of this invention to provide a multiple fluid system having means for combining two or more fluid streams.

A further object is to provide a fan that will draw gases from one source and mix them with inert or reactive gases from a second source, and,

means for controlling the relative amount of the gases from the two sources thereby controlling the composition, temperature, volume, velocity, and static pressure of the discharged gases.

5 More specifically, it is an object of this invention to provide means whereby a current of a relatively cool fluid is passed with hollow impeller shaft and blades to control the temperature thereof while a second stream of relatively hot fluid 90 is drawn into the fan chamber, commingled with the relatively cool fluid stream and discharged from the fan chamber.

A further object of this invention is to cause a stream of cool air to pass within the hollow im- 25 peller shaft and blades to cool the fan while the impeller blades are drawing hot combustion gases or flame from a furnace, commingling the cool 1 air and combustion gases within the fan chamber and discharging the stream of combined .air 30 and combustion gases into a drier.

A further object is to provide'a fan into which a reactive or inert gas can be admitted through the hollow hub and impeller blades of the fan to control the temperature of the fan parts and to 35 efiect the physical condition of the discharge gas by, means of mechanical or chemical combination of the gases.

A further object is to provide a fan that will draw hot gases from a furnace and mix them 40 with cold air, and means for controlling the amount ofcold air thereby allowing control of the temperature of the gases delivered to the drier.

' A further object is to provide a metal fan that 4,5 will operate at a temperature at which the metal will ordinarily become overheated.

A further object is to provide a fan into which cold air can be admitted through the shaft and through the blades of the fan keeping these parts 50 cool.

With the above and other objects in view, the invention resides in the combination and arrangement of parts as hereafter set forth, shown in the drawings, described and claimed, it be- 5 ing understood that changes in the precise cmthe scope of what is claimed without departing from the spirit of the invention.

In the drawings:

Figure 1 is a side elevation of the fan. 5

Figure 2 is a top plan view of the fan showing the same in connection with a conventional form of furnaceand drier.

Figure 3 is a vertical longitudinal sectional view through the device taken on line 33 of Figure 2. 10 Figure 4 is a vertical transverse sectional view through the fan.-

Figure 5 is a vertical longitudinal sectional view of another embodiment of my invention.

Referring to the drawings, the numeral l designates a portion of a conventional form of brick furnace, 2 the fan casing and 3 a portion of a conventional form of drier. Disposed within the casing 2 is a rotary fan 4, which sucks air from the furnace I throughthe pipe 5 and discharges the same through the pipe 6 to the drier.

It has been found in driers that where the flames are sucked from the furnace I to the fan and discharged to,the drier, the direct flames cause the fan, its hub and its bearings to become distorted incident to the high temperature. I Therefore, to overcome this objection a controlled flow of cold air is passed through the fan huh I, which has a chamber 8 therein, and through the fan blades 9. The current of cold air is supplied by an auxiliary fan I carried by the cold air supply pipe H and may be further controlled by a conventional form of damper l2; The cold air passesthrough pipe It and through the perforations l3 into the chamber 8 of the hollow fan hub l, and thence through'the perforations M into the chambers l5 of the fan blades 9, and discharged through the ports [6 at the tips of the fan blades and mixes with the gases sucked from the furnace by the fan, thereby cooling said gases 40 according to the amount of fresh air supplied.

It will be noted that this cool air passing through the hub and blades wipes the walls thereof, thereby cooling the same against the action of the high temperature of the gases and prevents warping or twisting of theseparts incident to the heat. The fan blades 9 are preferably provided with connecting ribs H, which act as cold conductors, also brace the fan walls and form pockets for distributing the cold air throughout the blade.

The hollow hub I is carried by a drive shaft H8 in axial relation thereto and is centered thereon by means of radially disposed bolts l9 threaded through the huh 'I and into engagement with the periphery of the shaft 18.1 Therefore, it will be seen there is no danger of the hub becoming fused or stuck to the shaft. The drive shaft 18 is rotatably mounted in bearing members 20 mounted on bearing blocks 2| and is provided with a drive pulley 22 overwhich a belt may be placed for driving the fan.

Referring toFiguIe' 5, the hollow hub l is extended and rotatably mounted in bearing members 20, supported on bearing blocks 2|, and is provided with a drive 'pulley 22. In this embodiment the supply pipe ll communicates with the chamber 8 within the hollow hub 1 beyond the bearings and drive pulley. Tn this manner the driving means may be placed nearer to the impeller blades thereby reducing the mechanical difliculties caused by vibration and overheating of the bearings. The supply pipe ll may be connected to the chamber of hollow hub I either as lllustrated in Figure 3 or as in Figure 5. That is, the supply pipe I l or II" may either abut one end of or surround the hollow hub I. When the supply pipe surrounds the hollow hub it is necessary to provide perforations l3 in hub l as illustrated in Figure 3.

From the above it will be seen that the drier fan is provided which will suck hot gases and flame direct from a furnace and discharge the same into a drier and during the operation of the fan a cooling current of air is passed therethrough for cooling the fan and reducing the temperature of the gases discharged to the drier.

While I have described my invention in terms of cool air and hot combustion gas, it is contemplated that any other inert or reactive fluid may be substituted for ,either the cold air or hot combustion gases. It is within this invention to com- -bine'reactive gases within the fan chamber to erties of the material being dried. For example, 'I contemplate the treating of citrus waste materials with combustion gases containing an added material which may, for example, be absorbed by the citrus waste and affect the acidity or alkalinity thereof. The hot combustion gases effectively dry the treated citrus waste as it passes through a suitable drier or drying apparatus, as shown, for example, by my U. S. Patent 2,026,922.

This application is a continuation-in-part of my copending application Serial No. 171,125, flied October 26, 1937.

The invention having been set forth, what is claimed as new and useful is:

1. A hot gas suction fan comprising a casing,-

a hollow rotatable hub within the casing and extending from one side thereof, a acid gas duct surrounding the hub outside the casing, an impeller within said cold gas duct, ports in the hub within the duct, chambered blades carried by said hub, perforations in the hub in communication with the chambers of the blades and means for discharging the cold gas through the blades and into the fan casing in a plurality of jets.

2. A device as set forth in claim 1 in which said means includes spaced walls within the chambers of the blades and forming a plurality of chambers in each blade in communication with the chamber of the hub through perforations in the hub.

3. A device as set forth in claim l in which said means includes perforations inthe hub, discharging into the blades, which are larger than the perforations in the hub in communication with the cold air duct.

4. An apparatus for impelling and mixing gases, said apparatus comprising a casing having a plurality of inlets arid a single outlet, a source of hot gases communicating with said casing, a hollow rotatable hub within the casing and extending from one side thereof, a cooling fluid duct communicating outside the casing with ports in the hub, a plurality of chambered blades carrled by said hub, perforations in the hub communicating with the hollow chambers of the said blades, positivemeans for discharging the said cooling fluid from said fluid duct through the blades into the fan casing.

5. A fan for impelling hot gases, said fan comprising a casing, a hollow hub with ports in. the periphery thereof, said ports communicating with chambers of hollow fan blades, means for controlling the temperature of said fan blades, said means including a cooling fluid duct communicating with said hollow blades through the said ports in said hollow hub, a controlled and positive supply of cooling fluid, impeller means for forcing controlled amounts of the said cooling fluid successively through the hollow hub and the hollow blades to cool the entire walls of the hollow blades and thence uniformly to commingle with the hot gases within'the casing.

6. A fan for impelling hot gases, said fan com-- prising a casing, a hollow hub with ports in the periphery thereof, said ports communicating with the hollow portions of single unit hollow fan blades having radially disposed heat radiating webs to brace and subdivide the blades into a plurality of chambers, means for controlling the temperature of said fan blades, said means including a cooling fluid duct communicating with said hollow blades through said hollow hub, a controlled and positive supply of cooling fluid, impeller means for positively forcing controlled amounts of the said cooling fluid successively through the hollow hub and the hollow blades to cool the entire walls of the hollow blades and thence uniformly to commingle with the hot gases within the casing.

7. A fan for impelling hot gases, said fan comprising a casing, a hollow hub with ports in the periphery thereof, said ports communicating with the hollow portions of single unit hollow fan blades having radially disposed heat radiating webs to brace and subdivide the blades into a plurality of chambers, means for controlling the temperature of said fan blades, said means including a cooling fluid duct communicating with said hollow hub, a controlled and positive supply of cooling fluid comprising, a secondary impeller within the cooling fluid duct for positively forcing controlled amounts of the said cooling fluid successively through the hollowhub and the hollow blades to cool the entire walls of the hollow blades and thence uniformly to commingle with the hot gases within the casing.

8. A fan for impelling hot gases and including means for controlling the temperature therof, said fan comprising a casing and an impeller, said impeller comprising a hollow hub upon which is mounted a plurality of hollow, chambered -blades extending outwardly from said hub, each of said blades being partitioned into a plurality of chambers. perforations in said hub co'mmunicat-' the casing, a secondary impeller within the coolin: with said chambers in each blade and each in: fluid duct to force the cooling fluid. succesbiadehaving a plurality of restricted orifices adsively through perforations in the hollow hub iacent the outer end oi'said blade, one end of and through the hollow blades into the casing said hollow hub being within the casing and to commingle all of said cooling fluid with the v5 1 sealed with respect thereto, a cooling fluid duct hot gases in controlled amounts.

communicating with said hollow hub exterior of DANIEL BOSCAWEN VINCENT. 

